Hitherto, a vending machine for a hotel room of the type described above has been formed into a product called "hotel vending system", in which it is desired that sales data are read or calculated easily and accurately. The vending machine in a hotel guest room of the type as described above generally includes a wired system connected between each guest room and a front information or cashier desk through a transmission line, and a wireless system or a so-called check key system for storing sales data in a memory element incorporated into an exclusive-use key holder and reading them out at the time of check out.
In the wired system, wiring work between each room and the front desk is difficult to perform after the hotel has been constructed, and even during the construction, construction costs increase and in addition, it is difficult to change or modify the system. For these reasons, the wireless system is more preferable. However, in the wireless system, that is, in the system in which an IC memory or the like is incorporated into the key holder to store sales data therein, the memory capacity is limited so that unlimited selling is impossible, because of the limitation of storable sales data. Even in the wired system, when the format for transmission of data is once determined, the number of articles to be sold is limited, due to the transmission capacity.
In a prior art vending refrigerator, discharge ports for sales articles are allotted to each kind of article. Sales data, for example, consisting of 4-bit article code and a sales number are stored in an IC memory within a key holder in case of a wireless system. In case of a wired system, such sales data are once stored, and then the stored sales data are transmitted to a hotel front desk. In this case, since the article code of 4 bits is stored or transmitted by allotting one code to each of sales articles, the efficiency of data memory or data transmission is low.
Generally, at least ten kinds of articles are retained in a refrigerator in a hotel guest room and hence, the article code is usually formed by at least 4 bits as described above. It would be necessary that 20 to 30 articles are retained for sales to satisfy the need of hotel guests and accordingly a memory capacity or transmission capacity of 128 bits, for example, is required. Further, while such a sales number seems to be excessive at a glance, it sometimes happen in a hotel that the guests sometimes stay for many consecutive days and that many guests often stay in one room and use a single refrigerator by a group of guest. Thus, it is necessary that sales data of this bit size is stored or transmitted at a time.
On the other hand, the vending refrigerator installed within the guest room is often subjected to inadequate manipulation resulting from unfamiliarity of use of the refrigerator by a guest or to undue manipulation resulting from intentional vandalism or mischief. If such an inadequate manipulation should all be called "Vandalism", the vandalism would cause a sensor portion to be tampered or inadequate delivery of articles to be repeated resulting in a possible destruction of sales data. Particularly, the vandalism within a closed guest room is unexpectedly severe, and thus, the vending machine in a guest room is required to withstand such vandalism. In a prior art system in which sales data such as article code, sales number or the like are produced and stored at every time of sales operation, there is a great possibility that sales data are destroyed, and it is difficult to restore the thus destroyed sales data and therefore the prior art system cannot stand against such vandalism.
On the other hand, in the so-called wireless system, article sales data to be modified at every time that an article is sold are stored in an external shift register contained in a key holder or the like. A guest or user presents the key holder to the front desk at the time of check-out, so that a settlement is made on the basis of article sales data obtained from the shift register. In order to modify the article sales data at every time that an article is sold, the previous article sales data stored in the external shift register are read out to be transferred to a data processing control circuit in a vending machine, where article sales data are modified in accordance with the sold articles and the modified article sales data rewritten in the shift register as the external memory. However, when modifying and rewriting of such article sales data, there is the possibility of an occurrence of various troubles such as an error in the modification of article sales data due to contact failure of various parts or erroneous operation of apparatus.
More specifically, the shift register provided in the key holder of the vending machine for a guest room stores, in the form of a predetermined format, article sales data composed of, for example, a room number (address), an article sales number for each kind of articles, and various control signals. On the other hand, a room number is correspondingly set in a controller for processing article sales data in a vending machine installed in each guest room. When the key holder is inserted into the controller, the shift register within the key holder is connected to the circuit within the controller so that the room number read from the shift register is first collated with the room number set in the controller. Unless both the numbers coincide with each other, the key is rejected. As a result, a condition of articles sales is not enabled. In order to provide such collation of room numbers, it is necessary to read data stored in the shift register and to transfer them to the controller.
In order to read out and transfer the data stored in the shift register, it is usual that a clock pulse is applied to the shift register to successively shift the data stored in the shift register so that the data is derived from the output end. This means that the shift register becomes vacant. Accordingly, if both the room numbers coincide with each other, normal sales procedure is taken without trouble. On the other hand, if both the room numbers do not coincide with each other, the data stored in the shift register within the key holder are disappeared, while the controller is returned to its original waiting condition. Therefore, the key holder cannot be used in the room with this number. With this in view, it is necessary that another memory means is provided in the controller, so that data transferred from the shift register is once stored in this memory means, and that prior to the rejection of a key in case the inconsistency of the room numbers the data is read from the memory means so that the data is returned to the shift register in the key holder.
Thus, the prior art vending machine in a hotel guest room is required to provide an additional memory means for the safeguard against the destroy of data, if the room numbers are inconsistent, so that the stored data read out from the shift register is returned to the shift register from the controller to restore the initial condition in the shift register. The provision, however, of such an additional memory means only for the safeguard results in the decrease of a usage efficiency of memory means.
In the controlling unit of the vending machine for hotel guest room, use is made of a 4 bit one chip microcomputer, for example, for the purpose of decreasing its cost and for increasing functions. However, a memory capacity of memory circuits (ROM, RAM) in the 1 chip microcomputer is limited. An internal RAM merely has a capacity of about 4.times.128 bits at the maximum. Thus, the occupation of a part (for example, 36 bits) of the RAM only for temporarily storing data (for example, 36 bits) in the register within the key holder greatly decreases a usage efficiency. In addition, there is a disadvantage that the transmission and reception of data between the register and another memory means results in a great possibility in that an error in data may destroy the original data.